SALIVA THE MIRACLE FLUID
Saliva is something that we take for granted. However, it plays may roles for our general health. From a dental point of view, its most important role is a fluid of decay prevention. Saliva covers the teeth and gums and provides a coating that helps protect the teeth from sugars and acids. It also contains bacteria that help maintain a balance between good and bad bacteria. For people that have maladies that prevent their saliva glands from producing saliva, or for those people that are on large doses of medication that interfere with saliva production, the lack of saliva makes decay more likely.
Saliva is also the first step in the process of digestion. Bacteria and chemical elements in saliva begin the process of digestion during mastication and help is digest our food.
Saliva contains enzymes, proteins and immunoglobulins, bacteria and their byproducts, host DNA and RNA, host cells and steroid hormones, ions and volatile compounds. All of these elements make saliva a wonderful diagnostic tool. A recent consortium of three research groups published the salivary proteome, identifying 1,166 proteins in human saliva. These proteins are involved with various levels of structural function and immune response, providing information that researchers have shown can be analyzed with a chairside or at-home test, taking just three to 10 minutes.
The best clinical diagnostic we have for gingivitis and periodontitis today is bleeding on probing, with the absence of bleeding being the more accurate predictor of health. Not all bleeding on probing leads to bone loss. Saliva contains proteins of both host and bacterial origin, providing new information about onset and progression of disease. It contains the bacteria associated with periodontal disease and the host response mediators including IgA, IL-1, MMP-8, and C-reactive protein. Gingival crevicular fluid mixes with saliva to provide immediate information about what’s happening inside the sulcus or periodontal pocket. Salivary markers provide information about the bacteria present in the pocket, inflammation, collagen breakdown and bone turnover.
Saliva is already used to determine hormone levels for estradiol, progresterone, testosterone, and cortisol. It is also used for drug testing of both legal and illegal drugs. Salivary diagnosis is now possible for oral cancer, breast cancer, salivary gland disease, hepatitis, HIV, and Sjogren’s Syndrome. These recent research finding are just the start.
Seven research grants were awarded by the National Institute of Dental and Craniofacial Research for microelectromechanical systems for salivary diagnostics or “lab-on-a-chip” prototypes. The Oral Fluid NanoSensor Test is one of these prototypes. It’s a handheld, automated, oral fluid sensor for rapid detection of multiple salivary proteins. Screening chips are designed with information to test against the saliva. The screening chip is the size of a credit card and is inserted into the machine along with the salivary sample with diagnostic data transferred to a Blackberry or iPhone type computer. Data chips have been designed and tested for oral cancer screening, Sjogren’s Syndome screening and perio screening with C-reactive protein, MMP-8 and IL-1.
Using this technology to measure nicotine metabolites with a 10-minute, in-office test for general practice patients in a smoking cessation program proved more successful than traditional approaches. A higher smoking cessation rate of 23 percent vs. seven precent was achieved with immediate data feedback to the subjects using the salivary diagnostic test.
It won’t be long before dentists and dental hygienists have greater involvemente in the identification and monitoring of oral and systemic diseases. Incredible, edible spit will eventually be the fluid of choice for clinical diagnostics.
From a article by Trisha E. O’Hehir RDH, February 2010 issue of Dental Ecomonics